Supplementary Material

Endoscopic resection of a trigeminal nerve meningioma centered in the left sphenoid bone at the foramen of rotundum. The patient is a 45 year old female who presented with left jaw and ear pain. She was noted to have a solidly enhancing lesion within the lateral inferior left sphenoid sinus with involvement of the foramen rotundum. The “two-nostrils-four-hands” endoscopic approach by a combined neurosurgical-otolaryngologic team was used to access the tumor with the assistance of real-time CT-guided navigation. Approach to the skull base tumor was undertaken by first performing a left partial middle turbinectomy, followed by a medial maxillectomy and complete sphenoethmoidectomy on the left side (not shown). A partial posterior septectomy was also performed to allow binaural access. Subsequently, the entire floor of the sphenoid sinus was taken down using a combination of high speed drill, Tru-Cut rongeurs and Kerrison punch until the tumor capsule was exposed. The Vidian canal was identified inferior to the lesion. After circumferentially exposing the tumor, dissection of the tumor from the dura of the middle fossa ensued using curettes and suction. The tumor capsule was then opened sharply with an endoscopic knife. Complete resection of the tumor through the foramen rotundum was achieved. Closure of the bony defect included an overlay of synthetic collagen matrix and free septal graft.